add: log management module (compressor, manager, retention)

internal/log/compressor.go

@@ -0,0 +1,225 @@
+package log
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+	"time"
+)
+
+var rawLogRe = regexp.MustCompile(`^homed_(\d{4}-\d{2}-\d{2})_\d{2}-\d{2}-\d{2}\.log$`)
+var weekRe = regexp.MustCompile(`^week_(\d{4})-W(\d{2})\.tar\.gz$`)
+var monthRe = regexp.MustCompile(`^month_(\d{4}-\d{2})\.tar\.gz$`)
+
+type fileGroup struct {
+	name string
+	files []string
+}
+
+func compressWeekly(logDir string) error {
+	entries, err := os.ReadDir(logDir)
+	if err != nil {
+		return err
+	}
+
+	groups := make(map[string][]string)
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+		m := rawLogRe.FindStringSubmatch(e.Name())
+		if m == nil {
+			continue
+		}
+		t, err := time.Parse("2006-01-02", m[1])
+		if err != nil {
+			continue
+		}
+		y, w := t.ISOWeek()
+		key := fmt.Sprintf("%04d-W%02d", y, w)
+		groups[key] = append(groups[key], e.Name())
+	}
+
+	for key, files := range groups {
+		dst := filepath.Join(logDir, fmt.Sprintf("week_%s.tar.gz", key))
+		if fileExists(dst) {
+			continue
+		}
+		sort.Strings(files)
+		if err := tarGzFiles(logDir, dst, files); err != nil {
+			return fmt.Errorf("compress week %s: %w", key, err)
+		}
+		for _, f := range files {
+			os.Remove(filepath.Join(logDir, f))
+		}
+	}
+	return nil
+}
+
+func compressMonthly(logDir string) error {
+	entries, err := os.ReadDir(logDir)
+	if err != nil {
+		return err
+	}
+
+	groups := make(map[string][]string)
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+		m := weekRe.FindStringSubmatch(e.Name())
+		if m == nil {
+			continue
+		}
+		key := fmt.Sprintf("%s-%s", m[1], m[2][:2])
+		monthKey := key[:7]
+		groups[monthKey] = append(groups[monthKey], e.Name())
+	}
+
+	for monthKey, files := range groups {
+		dst := filepath.Join(logDir, fmt.Sprintf("month_%s.tar.gz", monthKey))
+		if fileExists(dst) {
+			continue
+		}
+		sort.Strings(files)
+		if err := tarGzFiles(logDir, dst, files); err != nil {
+			return fmt.Errorf("compress month %s: %w", monthKey, err)
+		}
+		for _, f := range files {
+			os.Remove(filepath.Join(logDir, f))
+		}
+	}
+	return nil
+}
+
+func compressYearly(logDir string) error {
+	entries, err := os.ReadDir(logDir)
+	if err != nil {
+		return err
+	}
+
+	groups := make(map[string][]string)
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+		m := monthRe.FindStringSubmatch(e.Name())
+		if m == nil {
+			continue
+		}
+		yearKey := m[1][:4]
+		groups[yearKey] = append(groups[yearKey], e.Name())
+	}
+
+	for yearKey, files := range groups {
+		dst := filepath.Join(logDir, fmt.Sprintf("year_%s.tar.gz", yearKey))
+		if fileExists(dst) {
+			continue
+		}
+		sort.Strings(files)
+		if err := tarGzFiles(logDir, dst, files); err != nil {
+			return fmt.Errorf("compress year %s: %w", yearKey, err)
+		}
+		for _, f := range files {
+			os.Remove(filepath.Join(logDir, f))
+		}
+	}
+	return nil
+}
+
+func tarGzFiles(baseDir, dst string, filenames []string) error {
+	f, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	gw := gzip.NewWriter(f)
+	defer gw.Close()
+
+	tw := tar.NewWriter(gw)
+	defer tw.Close()
+
+	for _, fn := range filenames {
+		path := filepath.Join(baseDir, fn)
+		info, err := os.Stat(path)
+		if err != nil {
+			continue
+		}
+		header, err := tar.FileInfoHeader(info, "")
+		if err != nil {
+			continue
+		}
+		header.Name = fn
+		if err := tw.WriteHeader(header); err != nil {
+			return err
+		}
+		r, err := os.Open(path)
+		if err != nil {
+			return err
+		}
+		if _, err := io.Copy(tw, r); err != nil {
+			r.Close()
+			return err
+		}
+		r.Close()
+	}
+	return nil
+}
+
+func fileExists(path string) bool {
+	_, err := os.Stat(path)
+	return err == nil
+}
+
+func lastWeekKey(t time.Time) string {
+	y, w := t.ISOWeek()
+	return fmt.Sprintf("%04d-W%02d", y, w)
+}
+
+func lastMonthKey(t time.Time) string {
+	return t.Format("2006-01")
+}
+
+func lastYearKey(t time.Time) string {
+	return t.Format("2006")
+}
+
+func parseWeekKey(key string) (time.Time, error) {
+	var y, w int
+	if _, err := fmt.Sscanf(key, "%04d-W%02d", &y, &w); err != nil {
+		return time.Time{}, err
+	}
+	return firstDayOfISOWeek(y, w), nil
+}
+
+func firstDayOfISOWeek(year, week int) time.Time {
+	jan1 := time.Date(year, 1, 1, 0, 0, 0, 0, time.UTC)
+	_, jan1Week := jan1.ISOWeek()
+	daysOffset := (week - jan1Week) * 7
+	t := jan1.AddDate(0, 0, daysOffset)
+	for t.Weekday() != time.Monday {
+		t = t.AddDate(0, 0, -1)
+	}
+	return t
+}
+
+func listArchives(logDir, prefix string) []string {
+	entries, err := os.ReadDir(logDir)
+	if err != nil {
+		return nil
+	}
+	var result []string
+	for _, e := range entries {
+		if !e.IsDir() && strings.HasPrefix(e.Name(), prefix) {
+			result = append(result, e.Name())
+		}
+	}
+	return result
+}